我需要对二进制搜索树进行有序遍历,并且需要打印所有节点及其所在的级别,但是我想不出一种方法。
例如:
如果我有这个 bst,输出为:
4 #1
5 #0
9 #1
7 #2
10 #2
18 #3
到目前为止,这是我得到的:
这是我正在使用的结构:
struct tree {
int number;
tree *izq;
tree *der;
};
typedef struct tree *bst;
这是我要实现的功能:
void printTree(bst node) {
if (node==NULL) {
return;
}
else {
if (node->left != NULL) {
printTree(node->left);
}
printf("%d", node->number);
if (node->right !=NULL) {
printTree(node->right);
}
}
}
有人有什么想法吗?谢谢:)
答案 0 :(得分:1)
我使用Java实现了此功能,但我认为您可以轻松地将其转换为C:
private static void printWithLevels(TreeNode node) {
printWithLevels(node, 0);
}
private static void printWithLevels(TreeNode node, int level) {
if (node == null) return;
System.out.println(node.value + "(" + level + ")");
printWithLevels(node.left, level + 1);
printWithLevels(node.right, level + 1);
}
为使我的解决方案更完整,这是我对TreeNode的简单/快速实现:
private static class TreeNode {
int value;
TreeNode left;
TreeNode right;
TreeNode(int value, TreeNode left, TreeNode right) {
this.value = value;
this.left = left;
this.right = right;
}
}
答案 1 :(得分:0)
警告
struct tree {
int number;
tree *izq;
tree *der;
};
必须
struct tree {
int number;
struct tree *izq;
struct tree *der;
};
因为在开始时检查了节点为NULL的情况,所以可以简化:
void printTree(bst node) {
if (node != NULL) {
printTree(node->izq);
printf("%d", node->number);
printTree(node->der);
}
}
添加级别:
void printTree(bst node, int lvl) {
if (node != NULL) {
printTree(node->izq, lvl + 1);
printf("%d #%d\n", node->number, lvl);
printTree(node->der, lvl + 1);
}
}
然后您在根级别调用0
制作完整的程序:
#include <stdio.h>
#include <stdlib.h>
struct tree {
int number;
struct tree *izq;
struct tree *der;
};
typedef struct tree *bst;
void printTree(bst node, int lvl) {
if (node != NULL) {
printTree(node->izq, lvl + 1);
printf("%d #%d\n", node->number, lvl);
printTree(node->der, lvl + 1);
}
}
struct tree * mk(int v, struct tree * l, struct tree * r)
{
struct tree * t = malloc(sizeof(struct tree));
t->number = v;
t->izq = l;
t->der = r;
return t;
}
int main()
{
struct tree * r = mk(5, mk(4, NULL, NULL), mk(9, mk(7, NULL, NULL), mk(10, NULL, mk(18, NULL, NULL))));
printTree(r, 0);
}
编译执行:
pi@raspberrypi:/tmp $ gcc -pedantic -Wall -Wextra c.c
pi@raspberrypi:/tmp $ ./a.out
4 #1
5 #0
7 #2
9 #1
10 #2
18 #3